Vertical sliding access door



Feb. 15, 1955 R. A. FRlTZ VERTICAL SLIDING ACCESS DOOR 2 Sheets-Sheet l Filed. April 24, 1951 IPM l I I I I l II #.Miiliuwk Id l l |lllllll.

. IN V EN TOR. Fado/pl? H. Fiz BY Feb. 15, 1955 R. A. FRITZ 2,701,896

VERTICAL SLIDING ACCESS DooR v Filed April 24, 1951 2 sheets-shed 2 United States Patent O Cincinnati; hio, doing business as Chase IndustrialA lefrigerator vEquipment and Engineering Co., Reading,

hio

Application. April '24; 1951, Seri'aI'No. 222,603)

12 Claims. (Cl.` 20-19) The present invention relates to` improvements in vertical sliding access doors, such as may be employed in providing for the passage of articles and persons into and from cold storage rooms or other compartments.

An object of theinvention is to provide means in a vertical sliding access door structure, wherebyxa tight t is effected between the door and theframe only when the door is closed, whereas -at all positions of the door intermediate the upper andlower limits of travel, move.- ment of the door is attended by. aV negligible amount of dragor friction. Thus, the' structure is characterized by unusual ease of operation.

A further object is to'so' construct a`device of thev character stated, that-gasket' wear is virtually ellminated' and maintenance cost reduced to `a practical minimum.'

Another'object of the invention-is to eliminate binding` of moving'` parts, and frictional wear withy defacement of surfaces which are normally exposed to view,

so that the structure will present ai pleasing and'newappearance even after h-'aving been in usefor a'con-` siderable period of'time. l

Another objectf is tof' provide' a devicel ot" the character above referredto, which' is simple and 'inexpensive to manufacture and install', the` construction beingI such that any needed' repairs or replacementsof parts can be performed at slight cost in .laborandmaterials The foregoing and' otherv objectsarer attained bythe means described' herein and" illustrated uponthe a'ccompanying `drawings,` in which Fig. l is a front'elevational" view ofitheiimprove'd device; showing the: sliding door in fully open` raised position.

Fig.' 2 is a verticalsectionl takenf'online'r2-2fof`Fig. l,V showing .the structure on z a'V slightly .enlarged scafleand with the 'sliding door removed'.Y

Fig; 3 is aU frag-mentalfperspectiver View Aon 1an'fen` larged scale, showing the left side oflief-sliding'door depicted in Fig. l. Eig. .df/Pisisanifenlargedt'fragment'alr'cross-sectional` View taken ron ne= 4`^i4f=ofe1Figtfltf FigJLSLis :an: enlarged i fragmentalf cross sectiohalfview taken1 on line S-LS :of Figs: l; v

Fifg isar-Ian'iend :View vof' .the ."resilientfrplunger*-` unit shown-` irx:elevationaluponfFig: 5'.

Figtz'vis anview similarito'frFigs 2,: showing-Lafmodifi'cation:

The` delvicfe'; ofl the? present invention' comprises two principal ipa`rts,1l namely;I a'irectangulanframe 1-2 and a vertically slid'ablrdoor 13 The` rear planar^face`1`4 of ftheffram'e -risi adapted1 'tof rest lagainst a 2 verticalvv apertured':wall '(notshown), which forms part -of--thef storage compartinentr'to whichY the access lmay -behad by wayf'of ther-device"oftherinvention:` The aforesaid aperturef'of'' the?. compartment' -wa-ll? will f register withvvthe apertur'eflS dn :theflowerA half of` frame"lzfaridthe'z frame will fbe bolted*or-:otherwise` 4xedly.secured;- agains't the wa'llwitlrrial'llcracks orT spaces suitablylled lor-:plugg'ed tol` avoid cold-lossf or rpassage fof fair :around the frame. Thisffmounting'i oiifthe'frarne'upon the wallf'isr performed in accordance'. with'fi practice @common V-in r the art, and forms nol part'of thefpre'sentinvention; It may here beno'ted 'that*frame"aperture"15' is.l not necessarily at floor level,2but may-'ber'locatedy atlthe'level of truck beds'forffrailway carfo'ors to'facilitatev-passage of goods orfartic'les'iintoiandf frornzthevstorage compartment.'v

' 112 .may-Aconsist off'asill 16, aheader.- 17', and -apair fof? spaced@ upright Stiles118l1secu`reci` together the side edgesL of -the door.V

2,701,896 Patented Feb. 15,- 1955 r2ice formed thereon as afmearis`- toguideth'e door througho'utfits vertical travelfwithin the frame; Rollers 23 on the'v` door'V cooperate withl the 'an'g'es 22 atopposite sides' of the frame', to'eliminate frictionv at the ange's 22' as the door is elevated and lowered' lengthwise' of" the frame.' The rollers mayl rotate'oni studs 24 anchored in theframework' 25'of the door; with th'e roll'ersj rotating in a plane which isparallel' tothe meanplane of the door, this' beingawertical plane.

Door'13 'may be constructed on arectangular framework of wood vor otherv suitable'materialf, having front and rear panels' 26'and 27, respectively; space'dfapart to provlde a compartnieiit'lil forinsulating material', not shown. Thev door may be covered wholly orY partly with aI cladding 29'of sheet metal orthe like, if desired: A` suitable handle-30 maybe applied at any convenient locationy on the'front of the'door to facilitate shifting' ofthel door vertically to open 'or' 'closed' positions." The door apertureY being` indicatedy at 15,' it-isreadily un?r derstoodt'th'at the4 door is vclosed when fullyy lowered',-l andlopen when-fullyfelevated'. v

Movements of they door are facilitated` byfu'see of a* counterbalancing-V mechanism,-which"may' be of any" ap proved type; Asherein di'sclo'sed"byf'wayffof-example; the counterbalance may be' inthe-form of -weightsf'Zl traveling'vertically intheways or compartments-Ztl-Zt),l and suspended by-chains,` cables, -ropes or otherexible suspension means 36- passingV over suitableY pulleys Ztl-32,opposite' ends ot` such-suspension meansbeing anchored to the weightsand to th'e--uppercorner4 areas of the door, as at 33- and-34, respectivelyf The'meth odf of anchoring isimmat'erialy to the-inv`ention,-`l and' may therefore -befconventionalf- A `stopor bumper -35 'may be' applied tof theaframe 12 at anyVV suitable location-,etto limit upwa-rde travelof f the door toopen position:v f

Asis-most clearly illust-ratedby Fig.y 3, the rear-face of the door carries exible or resilient gasket members marginally thereof, these being indicated f byrthe A characters'?, 38,'39. Vertical gasket members 38 are furnished at opposite sides of the door, 'whereas the'l gasket member at 37 spans the upper marginvof'the'same face of thev door and extends horizontally. A fourthgasket 39 is-appliedto the lower edge 40 lofV the door; :and is adapted. tot engage. the sill 16 ofthe 'frarnc'when the doorisI fully lowered.- The gasketsmay be rubber or rubber-like1 strips or pads tacked or adhesivelyapplied to-the door; however, other forms. ofy gasketsV or sealingmeans maybeV resorted to inY accordance: with proper engineeringpractice:

At allelevated or open positions ofthe door13, the gaskets carried thereby are spaced romrthe. frame. so that sliding of the doory vertically within. the-frame is accomplished without yfrictionalf contact' or drag .between the door gaskets and the frame.v However, as the door is lowered to a nearly closed position, .means come into play for automatically shiftingV the door laterally in such-manner as to bringthegaskets 38-38`-37 into face contact with adjacent parts of the-frame to-eiect a-seal, asfmaybest be understood byreferringto Figs. 2 and 4. Finally, inthe lfully lowered or closed position of the ldoor,` the lower gasket 39 impinges-upon the sillv16' to complete thel seal.` A sui-tablemechanism whereby the stated-action maybe accomplished, is described `below in detail.l

Referring tor'Figs. 1 and 2, it maybe noted that the framelZ` includesy vertical coplanar jamb areas 42-421- 43,f-from which the `door gaskets are spaced whenever the door is elevated' to any position above the lower limit offtravel.- The desired spacing may be maintained withthe-userof-opposed vertical'fstraig-ht guides or tracks 45,---451'cooperatingwithV -suitable -followers Vcarried by The followers may be lin the forrn of rollers 46 rotatably mounted upon studs 47 projecting horizontally from the side edges 48-48 of the door. Such rollers may be applied near the top and bottom portions of the door, and as shown in Fig. 3, will preferably rest in a common vertical plane so that the door in its vertical shifting movements will be guided along the tracks or rails 45 likewise in a Vertical plane, throughout the major portion of the movement. Upon reaching a point near the closing position, however, the door becomes free of the guiding influence of the straight tracks or rails 45, and is thereupon subjected to a laterally directed force which shifts the door bodily toward the jamb areas 42,-42-43, upon which the door gaskets seat flatwise to effect the desired seal.

The means utilized for displacing the door bodily toward the iamb areas of the frame as above related, may be in the form of resilient plunger or pusher units S interposed in the guideways provided by the tracks 45. Such units are best illustrated upon Figs. 2, and 6, and will be seen to comprise a tubular housing 51 having at least one open end 52 through which may proiect the plunger 53. The plunger is normally urged resilientlv outwardly by means of a compression spring 54 or otherwise, so as to dispose the nose end 55 of the plunger always partly across the track 45 and into the path of movement of a roller or follower 46. Opposed to the nose of the plunger is a stop or wedge block 56, screwed or otherwise secured to the frame side, and having inclined edges 57 to guide the roller 46 gently toward or from the iamb area, depending upon the direction of vertical shifting of the door 13. The crotch 58 of the wedge block may limit the extent of lateral shifting of the roller and the door toward the jarnb. The nose of the plunger may be complementary in shape to the shape of the crotch, as shown, and will include inclines 59-59. The nose of the plunger is located directly opposite the crotch of stop or block 56.

A convenient method of making the plunger unit 50, is to produce two channel-shaped stampings 60 and 61 (Fig. 6), one of which may fit over the other with the legs overlapping. This forms an elongate angular tube in which the plunger 53 may slide. The plunger may be slotted longitudinally as at 62 to receive the compression Spring 54. A screw or other fastener 63 passes through the body parts 60 and 61. and forms an abutment for one end of the spring. The opposite end of the spring abuts the end of the slot near the nose of the plunger. A second screw or fastener 64 secures the part 61 to the door frame. as does also the screw 63, to mount the unit upon the frame.

The parts S0 and 56 may be separately secured to the door frame as shown, but to facilitate application thereof in perfect alignment. these parts may first be mounted upon a thin plate which in turn may be secured to the frame as an assembled unit. In either case. the plunger nose 55 will extend partly across the track or line of travel of the roller 46, whereas the crotch 58 of block 56 will be disposed beyond the track an equal distance. The action of members 53 and 56 is that of displacing the roller 46 and door 13 toward the iamb areas of the frame, causing the gaskets to seat thereon for effecting a seal. The inclines 57-59 of said members force the lower door gasket 39 to seal against the sill 16, thereby completing the seal.

As will be understood by reference to Figs. l and 2, the door frame is provided with upper and lower pairs of plunger units Sti-56. spaced apart vertically a proper distance to ensure simultaneous displacing actions at both the upper and lower ends of the sliding door. when the door is lowered to closing position. In other words, the plunger units act simultaneously upon both of the rollers 46-46 shown in Fig. 3, and upon the similar rollers carried by the opposite side edge of the door. The vertical distance between an upper roller 46 and a lower roller 46, is the same as the distance between upper -andlower plunger noses. The stop or bumper means 35, however. is preferably located at such an elevation upon the frame as to preclude the lower rollers 46 of the door from engaging the upper plunger units when the door is fullv open. This is clearly indicated at 50-46, in the middle portion of Fig. 1.

In Fig. 2, the character 60 indicates a solid panel fixed in the frame to close the upper half thereof. It may be noted that the door gaskets can at no time rub `or chafe the finish of this panel, which is of course exposed to view when the door is lowered or closed,

and should therefore present a pleasing appearance.`

The structural frame part or cross piece 61 may constitute the top of the frame opening 15, and can furnish the jamb area against which the upper door gasket 37 may abut when the door is closed.

Referring now to the modification illustrated by Fig. 7, it may be noted that the frame in this form of the invention is identical to that of Fig. 2, the only difference being in the track structure indicated at 145-145, and the location of the rollers 146-147 upon the sliding door 113. Instead of having the track sections vertically aligned as in Fig. 2, the track sections of Fig. 7 are offset from one another a distance somewhat less than the door thickness, and in vertical spaced planes. The lower end 65 of the upper track section terminates at a point near the middle of the frame, and the lower end 66 of the lower track section terminates near the sill 16. At the lower ends of the track sections are located the plunger or pusher units 50-56, operative to laterally displace the sliding door toward the jamb areas 42 and 43, for the same purposes and in the same manner as was explained hereinbefore in the description of Figs. l to 6. Because of the offset relationship of the track sections, the rollers 146 and 147 of the sliding door are necessarily similarly offset upon the side edges of the door, as shown, so that the door in its vertical movement is always disposed in a vertical position.

It will readily be evident from the disclosure of Fig. 7, that lowering the sliding door 113 to a nearly closed position will bring the rollers or followers 146 and 147 under the influence of the plunger or pusher elements at Sil-56, with the result that the door finally will be shifted thereby or displaced laterally to place the door gaskets 37-38-39 in contact with the jamb areas 43-42-16, to effect the desired seal as the door is fully closed. The action to which the door is subjected in closing and opening, is the same as that described in conuection with the disclosure of Figs. l to 6. v

In conclusion, it is to be understood that various modiiications and changes in the structural details of the device may be made, within the scope of the appended claims, without departing from the spirit of the invention. For example, the sliding door may be counterbalanced by means other than that disclosed; the door and frame may be of all-metal construction, or of various combinations of materials suitable therefor; and the stop or bumper 35 may be applied otherwise than as shown, and in fact may be eliminated by substituting other means to limit upward travel of the sliding door.

Mounting of the frame 12 upon a wall may be effected by passing bolts, screws or other fasteners through the header and sill aprons 67 and 68, and possibly also through the frame stiles before the cladding 19 is finally applied to the frame.

What I claim is:

1. A sliding access door structure, comprising a frame having an opening therethrough, and coplanar jamb areas substantially bounding said opening, a sliding door movable along the frame to an operative position at which the door closes the opening, and to an inoperative position at which the opening is uncovered, said door having a face which traverses the jamb areas of the frame, and said face having margins to abut tlatwise upon the iamb areas of the frame, track means on the frame and followers on the door cooperating to guide the door in sliding from one said position to the other, the track means being in a plane parallel to the jamb areas, and spaced from the plane of the latter a distance such as to maintain a substantial clearance between the door face and the jamb areas of the frame during sliding of the door, said track means having terminal ends from which the followers emerge as the door is moved toward closed position and resilient plungers disposed beyond the terminal ends of the track means near opposite ends of the opening, to impose lateral force upon the door at substantially the closing position thereof, causing bodily shifting of the door toward the jamb areas of the frame.

2. A sliding access door structure, comprising a frame having an opening therethrough, and coplanar jamb areas substantially bounding said opening, a sliding door movable along the frame to an operative position at which the door closes the opening, and to an inoperative position at which the opening is uncovered, said door having a face which traverses the jamb areas of the frame, and

said: face havingmargins.. to abutatwise upon the'. jamb.

areas oflth'e, frame, :track fmeansY on the. frame, .and followers `on the :door cooperating.l tor-guide ,thegdoorin sliding'ifrom-one saidposition: tothe other, the track means beirrggin a plane parallel. 'to' the jambareas, Aand position and vresilient plungers' disposed beyond theterminal'ends of the .track means near opposite ends of the openng, to "impose .lateral force "upon thedo'or atVv sub# stantially the =closing fposition thereof, causing ,Y bodily shiftingV of the door. towardthe jambj'areas of' theA frame, and `ineans 'having inclines located oppositen the plungers, for-gently lguid'ingfzthe` followers ofthe-door onto and fr'mr' the track means aforesaid;

3:"A` vertical" slidirrgaccessVv door structure, `comprising an upright *frame* having an-V `openingktherethrough, and

coplanarl jamb tareas substantially bounding Hsaid opening-,z aheade'r atfthe-upper end. ofthe frame; a sill at'the lowerY end'thereof,` and yspaced' vertical stilesu connecting v.the sill to' the-headerga ldoor shiftable vertically along the lStilesr towar'deand-"fr'om the headerV and the sill,"the latter deiining'thelower' end of the'opening-aforesaid; anda member-Ourthe framelflocated substantially midway be saidopening-,said door including-a lower; end tov engage which `defines the upper end of t'heopening, said plungerseach having i a --we'dVge-'shaperl-A *nosef normally in the fpath' ofmovernentoflthe followers, for displacing the-:follow-4 ers and-the door'la'terally' toward the-jamb areas ofthe frme-whmtheuooris moved into close proximity with the sill, thereby to dispose the side =andfuppermarginstofv the door in abutting relationship upon thejamb areas aforesaid,membrs on-the-stiles opposed to each plunger and providing inclines toi. gently *'.guidezthe l displaced followers onto and from the track means while the plungers actuponsaid "followers, and ymeans limiting elevation of thedoorl to'ipreelude-engagement of -th llowerfollowers wi'thfl the uppenplungers Ywhen-the door is moved 'toward theeheader-.ry

4. A vertical sliding access door structure, comprising an upright frame having an opening therethrough, and coplanar jamb areas substantially bounding said opening, a header at the upper end of the frame, a sill at the lower end thereof, and spaced vertical stiles connecting the sill to the header, a door shiftable vertically along the stiles toward and from the header and the sill, the latter defining the lower end of the opening aforesaid, and a member on the frame located substantially midway between the sill and the header defining the upper end of said opening, said door including a lower end to engage the sill when the door covers the opening and is closed thereon, one face of said door having coplanar side and upper margins to coincide with the jamb areas of the frame bounding said opening, vertical track means fixed upon the stiles in opposing relationship, and upper and lower followers on the door cooperating with the track means to guide the door vertically in moving toward and from the sill, resiliently extended plungers interposed in the track means near the sill and that frame member which defines the upper end of the opening, said plungers each having a wedge-shaped nose normally in the path of movement of the followers, for displacing the followers and the door laterally toward the jamb areas of the frame when the door is moved into close proximity with the sill, thereby to dispose the side and upper margins of the door in abutting relationship upon the jamb areas aforesaid, members on the stiles opposed to each plunger and providing inclines to gently guide the displaced followers onto and from the track means while the plungers act upon said followers, and means limiting elevation of the door to preclude engagement of the lower followers with the upper plungers when the door is moved toward 'theV header, an"elongate' casing member cf'we'ringg` each stile',.-said.` casingA members each IincluLdingg@ flange, turned .inwardly at substantialyright angles to. thel plane of movement of the door established by thertrack 'means' and followerson'the'door ridingrupon saidi Aiia'ngesm. preclude shiftingA of the doorv toward' and; from-the Stiles.`

5. A vertical sliding access door: structure, comprising an upright frame having an: opening' therethrough, .andj

coplanar jamb -areas substantially Yboundngsaid opening,Y

a header 'at theupper end of theframe, a sill at the lower,l end thereof,` and spaced vertical Stiles connectingathe sill' to the header, a door shiftableifvertieallyfalongthe Stiles toward andffrom the header'andthe 'sill,,` the latter; de fining the` -lower -end ofthe `opening aforesaid,l yand a member-on `the frame located substantially nfidwayjbe-Y tween theasill-and 'theheader defining the upper end of', said opening, said'door-'includiriga lower end to-engagej the sill when the door covers-theopeningzandfisY closed thereon, one face of said door havingcoplanarside and upper margins to coincide-withthe. jamb kareas'. of they frame bounding said openingyverticaltrack means fixedy upon the stilesv in opposing relationship;-andj-upper -and lower followers on the door Vcooperating'witlr'the` track' means to guide the doorvertically-inv moving toward-and from the sill, resiliently extended? plungers interposedin the track means near theY sill andv that frameVV member which defines the upper-.endfof the openingesaid plungers; each having-va wedge-shaped nose-normally-intlie path4v of .movement of the-followers, for displacing the followv ers and-the door laterally Ytoward vthe -jambiareasof they frame lwhen" the ldoor is? moved into -close proximity fwith the sill, thereby-to dispose-theside and upper margins ofV the-door yin abutting relationship-upon the jamb areas aforesaid, members on'- .thef Stiles) opposed to-each'plunger and providing inclinesto gently guide -the'd'isplaeedl'folfl lowers onto and ffrom thetrackmeans while? the plungers act upon -said followers', janu'elongat'eHcasing-memberl covering each stile andformi-ng therewith 'a -vertic'al chair,y nel extendingfrom the 'headertovthe-sill, and meansf-in aidI channels: for -counterbalancingjthe' weightoffthe-- oor.

6. A vertical sliding accessdoor; structure,com-prising an upright frameY having Aan opening therethrough, and coplanar jamb" areas! substantially-boundingsaid opening,- a header-.at the-upperend offtheifralnle, ,a sill atithe lower vend thereof, andspaced? vertie'al stil'els: connecting thersill to `the header;V a Adoorlshifta'bleZ verticallyvalong the Stiles toward 'and'ffrorrr-the=heade`1- andwthesill, the latter defining thel lower endVof theopening-aforesaid; and a' member onthe frame;-locatedsubstantially midway between'A the 'fsillfand the "header defining the upperV end ofY-s'aid opening, saide door- 'in'cluding a -lowen yend* to en-` gageathef'sill whenrthedo'or covers -the opening and? 'is closed thereon, one face of said door having coplanar side and upper margins to coincide with the jamb areas of the frame bounding said opening, vertical track means fixed upon the Stiles in opposing relationship, and upper and lower followers on the door cooperating with the track means to guide the door vertically in moving toward and from the sill, resiliently extended plungers interposed in the track means near the sill and that frame member which defines the upper end of the opening, said plungers each having a wedge-shaped nose normally in the path of movement of the followers, for displacing the followers and the door laterally toward the jamb areas of the frame when the door is moved into close proximity with the sill, thereby to dispose the side and upper margins of the door in abutting relationship upon the jamb areas aforesaid, members on the stiles opposed to each plunger and providing inclines to gently guide the displaced followers onto and from the track means while the plungers act upon said followers, an elongate casing member covering each stile and forming therewith a vertical channel at one side of each stile, means in said channels for counterbalancing the weight of the door, flanges on said casing members at the opposite side of each stile, and followers on the door riding upon said channels to preclude shifting of the door toward and from the stiles.

7. A vertical sliding access door structure, comprising an upright frame having an opening therethrough, and coplanar jamb areas substantially bounding said opening, a header at the upper end of the frame, a sill at the lower end thereof, and spaced vertical stiles connecting the sill to the header, a door shiftable vertically along the stiles toward and from the header and the sill, the

latter defining the lower end of the opening aforesaid, and a member on the frame located between the sill and the header defining the upper end of said opening, said door including a lower end to engage the sill when the door covers the opening and is closed thereon, one face of said door having coplanar side and upper margins to coincide with the jamb areas of the frame bounding said opening, vertical track means fixed upon the stiles in opposing relationship, and upper and lower followers on the door cooperating with the track means to guide the door vertically in moving toward and from the sill, resiliently extended plungers interposed in the path of the track means near the sill and that frame member which defines the upper end of the opening, said plungers each having a wedge-shaped nose normally in the path of movement of the followers, for displacing the followers and the door laterally toward the jamb areas of the frame when the door is moved into close proximity with the sill, thereby to dispose the side and upper margins of the door in abutting relationship upon the jamb areas aforesaid, and members on the stiles opposed to each plunger and providing inclines to gently guide the displaced followers onto and from the track means while the plungers act upon said followers.

8. A vertical sliding access door structure, comprising an upright frame having an opening therethrough, and coplanar jamb areas `substantially bounding said opening, a header at the upper end of the frame, a sill at the lower end thereof, and spaced vertical stiles connecting the sill to the header, a door shiftable vertically l along the stiles toward and from the header and the sill, the latter defining the lower end of the opening aforesaid, and a member on the frame located between the sill and the header defining the upper end of said opening, said door including a lower end to engage the sill when the door covers the opening and is closed thereon, one face of said door having coplanar side and upper margins to coincide with the jamb areas of the frame bounding said opening, vertical track means fixed upon the Stiles in opposing relationship, and upper and i lower followers on the door cooperating with the track means to guide the door vertically in moving toward and from the sill, wedge members interposed in the path of the track means near the sill and that frame member which defines the upper end of the opening, said wedge members each having a nose normally in the path of movement of the followers, for displacing the followers and the door laterally toward the jamb areas of the frame when the door is moved into close proximity with the sill, thereby to dispose the side and upper margins of the door in abutting relationship upon the jamb areas aforesaid, and members on the Stiles opposed to each wedge member and providing inclines to gently guide p the displaced followers onto and from the track means while the wedge members act upon said followers.

9. A structure as specified in claim 8, and in which is included means limiting elevation of the door to preclude engagement of the lower followers with the upper wedge members when the door is moved toward the header.

10. A sliding access door structure, comprising a frame having an opening therethrough, and jamb areas substantially bounding said opening, a sliding door movable along the frame to an operative position at which the door close the opening, and to an inoperative position at which the opening is uncovered, said door having a face which traverses the jamb areas of the frame, sealing means extending from said door face toward the jamb areas,

means for guiding the door during the major extent of its travel, to maintain a clearance space between the door sealing means and the jamb areas of the frame, said guiding means comprising straight track sections at opposite sides of the frame, and upper and lower followers on the door riding upon said tracks, the track sections having ends spaced in substantial correspondency with the distance between the upper and lower followers so that the followers may simultaneously overrun the ends of the track sections as the door reaches closed position, and means beyond the lower ends of the track sections to displace the door laterally, placing the sealing means in contact with the jamb areas of the frame.

1l. A structure as specified in claimlO, and in which the means to displace the door comprises an incline at the lower end of each track section, directed obliquely toward the sill and the frame opening.

l2. A sliding access door structure, comprising a frame having an opening therethrough, and jamb areas substantially bounding said opening, means for slidably mounting the door including longitudinal guide tracks stationarily supported on the jamb areas adjacent the side edges of the door and anti-friction means engaging said tracks and stationarily mounted on the door adjacent the side edges thereof, and means associated with said guide tracks adjacent the ends thereof dimensioned to receive and laterally shift the anti-friction means for forcing the door toward and in contacting relationship with the jamb areas.

References Cited in the file of this patent UNITED STATES PATENTS 1,068,540 Stevens July 29, 1913 2,199,182 LeonardV Apr. 30, 1940 2,352,639 Kinish July 4, 1944 2,426 567 Snider Aug. 26, 1947 

